1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *  Driver for the Conexant CX23885 PCIe bridge
4  *
5  *  Copyright (c) 2007 Steven Toth <stoth@linuxtv.org>
6  */
7 
8 #include "cx23885.h"
9 
10 #include <linux/kernel.h>
11 #include <linux/module.h>
12 #include <linux/moduleparam.h>
13 #include <linux/init.h>
14 
15 static unsigned int vbibufs = 4;
16 module_param(vbibufs, int, 0644);
17 MODULE_PARM_DESC(vbibufs, "number of vbi buffers, range 2-32");
18 
19 static unsigned int vbi_debug;
20 module_param(vbi_debug, int, 0644);
21 MODULE_PARM_DESC(vbi_debug, "enable debug messages [vbi]");
22 
23 #define dprintk(level, fmt, arg...)\
24 	do { if (vbi_debug >= level)\
25 		printk(KERN_DEBUG pr_fmt("%s: vbi:" fmt), \
26 			__func__, ##arg); \
27 	} while (0)
28 
29 /* ------------------------------------------------------------------ */
30 
31 #define VBI_LINE_LENGTH 1440
32 #define VBI_NTSC_LINE_COUNT 12
33 #define VBI_PAL_LINE_COUNT 18
34 
35 
36 int cx23885_vbi_fmt(struct file *file, void *priv,
37 	struct v4l2_format *f)
38 {
39 	struct cx23885_dev *dev = video_drvdata(file);
40 
41 	f->fmt.vbi.sampling_rate = 27000000;
42 	f->fmt.vbi.samples_per_line = VBI_LINE_LENGTH;
43 	f->fmt.vbi.sample_format = V4L2_PIX_FMT_GREY;
44 	f->fmt.vbi.offset = 0;
45 	f->fmt.vbi.flags = 0;
46 	if (dev->tvnorm & V4L2_STD_525_60) {
47 		/* ntsc */
48 		f->fmt.vbi.start[0] = V4L2_VBI_ITU_525_F1_START + 9;
49 		f->fmt.vbi.start[1] = V4L2_VBI_ITU_525_F2_START + 9;
50 		f->fmt.vbi.count[0] = VBI_NTSC_LINE_COUNT;
51 		f->fmt.vbi.count[1] = VBI_NTSC_LINE_COUNT;
52 	} else if (dev->tvnorm & V4L2_STD_625_50) {
53 		/* pal */
54 		f->fmt.vbi.start[0] = V4L2_VBI_ITU_625_F1_START + 5;
55 		f->fmt.vbi.start[1] = V4L2_VBI_ITU_625_F2_START + 5;
56 		f->fmt.vbi.count[0] = VBI_PAL_LINE_COUNT;
57 		f->fmt.vbi.count[1] = VBI_PAL_LINE_COUNT;
58 	}
59 
60 	return 0;
61 }
62 
63 /* We're given the Video Interrupt status register.
64  * The cx23885_video_irq() func has already validated
65  * the potential error bits, we just need to
66  * deal with vbi payload and return indication if
67  * we actually processed any payload.
68  */
69 int cx23885_vbi_irq(struct cx23885_dev *dev, u32 status)
70 {
71 	u32 count;
72 	int handled = 0;
73 
74 	if (status & VID_BC_MSK_VBI_RISCI1) {
75 		dprintk(1, "%s() VID_BC_MSK_VBI_RISCI1\n", __func__);
76 		spin_lock(&dev->slock);
77 		count = cx_read(VBI_A_GPCNT);
78 		cx23885_video_wakeup(dev, &dev->vbiq, count);
79 		spin_unlock(&dev->slock);
80 		handled++;
81 	}
82 
83 	return handled;
84 }
85 
86 static int cx23885_start_vbi_dma(struct cx23885_dev    *dev,
87 			 struct cx23885_dmaqueue *q,
88 			 struct cx23885_buffer   *buf)
89 {
90 	dprintk(1, "%s()\n", __func__);
91 
92 	/* setup fifo + format */
93 	cx23885_sram_channel_setup(dev, &dev->sram_channels[SRAM_CH02],
94 				VBI_LINE_LENGTH, buf->risc.dma);
95 
96 	/* reset counter */
97 	cx_write(VID_A_VBI_CTRL, 3);
98 	cx_write(VBI_A_GPCNT_CTL, 3);
99 	q->count = 0;
100 
101 	/* enable irq */
102 	cx23885_irq_add_enable(dev, 0x01);
103 	cx_set(VID_A_INT_MSK, 0x000022);
104 
105 	/* start dma */
106 	cx_set(DEV_CNTRL2, (1<<5));
107 	cx_set(VID_A_DMA_CTL, 0x22); /* FIFO and RISC enable */
108 
109 	return 0;
110 }
111 
112 /* ------------------------------------------------------------------ */
113 
114 static int queue_setup(struct vb2_queue *q,
115 			   unsigned int *num_buffers, unsigned int *num_planes,
116 			   unsigned int sizes[], struct device *alloc_devs[])
117 {
118 	struct cx23885_dev *dev = q->drv_priv;
119 	unsigned lines = VBI_PAL_LINE_COUNT;
120 
121 	if (dev->tvnorm & V4L2_STD_525_60)
122 		lines = VBI_NTSC_LINE_COUNT;
123 	*num_planes = 1;
124 	sizes[0] = lines * VBI_LINE_LENGTH * 2;
125 	return 0;
126 }
127 
128 static int buffer_prepare(struct vb2_buffer *vb)
129 {
130 	struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
131 	struct cx23885_dev *dev = vb->vb2_queue->drv_priv;
132 	struct cx23885_buffer *buf = container_of(vbuf,
133 		struct cx23885_buffer, vb);
134 	struct sg_table *sgt = vb2_dma_sg_plane_desc(vb, 0);
135 	unsigned lines = VBI_PAL_LINE_COUNT;
136 
137 	if (dev->tvnorm & V4L2_STD_525_60)
138 		lines = VBI_NTSC_LINE_COUNT;
139 
140 	if (vb2_plane_size(vb, 0) < lines * VBI_LINE_LENGTH * 2)
141 		return -EINVAL;
142 	vb2_set_plane_payload(vb, 0, lines * VBI_LINE_LENGTH * 2);
143 
144 	cx23885_risc_vbibuffer(dev->pci, &buf->risc,
145 			 sgt->sgl,
146 			 0, VBI_LINE_LENGTH * lines,
147 			 VBI_LINE_LENGTH, 0,
148 			 lines);
149 	return 0;
150 }
151 
152 static void buffer_finish(struct vb2_buffer *vb)
153 {
154 	struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
155 	struct cx23885_buffer *buf = container_of(vbuf,
156 		struct cx23885_buffer, vb);
157 
158 	cx23885_free_buffer(vb->vb2_queue->drv_priv, buf);
159 }
160 
161 /*
162  * The risc program for each buffer works as follows: it starts with a simple
163  * 'JUMP to addr + 12', which is effectively a NOP. Then the code to DMA the
164  * buffer follows and at the end we have a JUMP back to the start + 12 (skipping
165  * the initial JUMP).
166  *
167  * This is the risc program of the first buffer to be queued if the active list
168  * is empty and it just keeps DMAing this buffer without generating any
169  * interrupts.
170  *
171  * If a new buffer is added then the initial JUMP in the code for that buffer
172  * will generate an interrupt which signals that the previous buffer has been
173  * DMAed successfully and that it can be returned to userspace.
174  *
175  * It also sets the final jump of the previous buffer to the start of the new
176  * buffer, thus chaining the new buffer into the DMA chain. This is a single
177  * atomic u32 write, so there is no race condition.
178  *
179  * The end-result of all this that you only get an interrupt when a buffer
180  * is ready, so the control flow is very easy.
181  */
182 static void buffer_queue(struct vb2_buffer *vb)
183 {
184 	struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
185 	struct cx23885_dev *dev = vb->vb2_queue->drv_priv;
186 	struct cx23885_buffer *buf = container_of(vbuf,
187 			struct cx23885_buffer, vb);
188 	struct cx23885_buffer *prev;
189 	struct cx23885_dmaqueue *q = &dev->vbiq;
190 	unsigned long flags;
191 
192 	buf->risc.cpu[1] = cpu_to_le32(buf->risc.dma + 12);
193 	buf->risc.jmp[0] = cpu_to_le32(RISC_JUMP | RISC_CNT_INC);
194 	buf->risc.jmp[1] = cpu_to_le32(buf->risc.dma + 12);
195 	buf->risc.jmp[2] = cpu_to_le32(0); /* bits 63-32 */
196 
197 	if (list_empty(&q->active)) {
198 		spin_lock_irqsave(&dev->slock, flags);
199 		list_add_tail(&buf->queue, &q->active);
200 		spin_unlock_irqrestore(&dev->slock, flags);
201 		dprintk(2, "[%p/%d] vbi_queue - first active\n",
202 			buf, buf->vb.vb2_buf.index);
203 
204 	} else {
205 		buf->risc.cpu[0] |= cpu_to_le32(RISC_IRQ1);
206 		prev = list_entry(q->active.prev, struct cx23885_buffer,
207 			queue);
208 		spin_lock_irqsave(&dev->slock, flags);
209 		list_add_tail(&buf->queue, &q->active);
210 		spin_unlock_irqrestore(&dev->slock, flags);
211 		prev->risc.jmp[1] = cpu_to_le32(buf->risc.dma);
212 		dprintk(2, "[%p/%d] buffer_queue - append to active\n",
213 			buf, buf->vb.vb2_buf.index);
214 	}
215 }
216 
217 static int cx23885_start_streaming(struct vb2_queue *q, unsigned int count)
218 {
219 	struct cx23885_dev *dev = q->drv_priv;
220 	struct cx23885_dmaqueue *dmaq = &dev->vbiq;
221 	struct cx23885_buffer *buf = list_entry(dmaq->active.next,
222 			struct cx23885_buffer, queue);
223 
224 	cx23885_start_vbi_dma(dev, dmaq, buf);
225 	return 0;
226 }
227 
228 static void cx23885_stop_streaming(struct vb2_queue *q)
229 {
230 	struct cx23885_dev *dev = q->drv_priv;
231 	struct cx23885_dmaqueue *dmaq = &dev->vbiq;
232 	unsigned long flags;
233 
234 	cx_clear(VID_A_DMA_CTL, 0x22); /* FIFO and RISC enable */
235 	spin_lock_irqsave(&dev->slock, flags);
236 	while (!list_empty(&dmaq->active)) {
237 		struct cx23885_buffer *buf = list_entry(dmaq->active.next,
238 			struct cx23885_buffer, queue);
239 
240 		list_del(&buf->queue);
241 		vb2_buffer_done(&buf->vb.vb2_buf, VB2_BUF_STATE_ERROR);
242 	}
243 	spin_unlock_irqrestore(&dev->slock, flags);
244 }
245 
246 
247 const struct vb2_ops cx23885_vbi_qops = {
248 	.queue_setup    = queue_setup,
249 	.buf_prepare  = buffer_prepare,
250 	.buf_finish = buffer_finish,
251 	.buf_queue    = buffer_queue,
252 	.wait_prepare = vb2_ops_wait_prepare,
253 	.wait_finish = vb2_ops_wait_finish,
254 	.start_streaming = cx23885_start_streaming,
255 	.stop_streaming = cx23885_stop_streaming,
256 };
257